Accumulator (bet)

A parlay, accumulator, or combo bet is a single bet that links together two or more individual wagers and is dependent on all of those wagers winning together. The benefit of the parlay is that there are much higher payoffs than placing each individual bet separately since the difficulty of hitting it is much higher. If any of the bets in the parlay lose, the entire parlay loses. If any of the plays in the parlay ties, or "pushes", the parlay reverts to a lower number of teams with the odds reducing accordingly.

Parlay bets are paid out at odds higher than the typical single game bet, but still below the "true" odds. For instance, a common 2-team NFL parlay generally has a payout of 2.6:1 if both picks are correct. In reality, however, if one assumes that each single game bet is a coin flip and would be expected to pay out at 1:1, the true payout should instead be 3:1, a substantial difference.

Mulroe places a three-team NFL parlay on the Packers, Bears, and Bengals. If any one of those teams fail to cover the spread, Mulroe loses his parlay bet. But if all three teams beat the spread, Mulroe gets paid $600 for every $100 bet.

If Mulroe pushes on one of those picks, he then has a two-team parlay. If he pushes on two picks, he would then have a straight bet.

Sam wagers £1,000 on Arsenal/Manchester United to draw, Chelsea to win, and Liverpool to win. Sam wins £6,072 as he correctly predicted all three results.

The calculation is: £1,000 × 3.2 × 1.7 × 1.3 = £7,072, less the stake of £1,000.

Sam wagers £1,000 on Manchester United to win, Chelsea to win, and Liverpool to win. He loses the wager if either Manchester United, Chelsea, or Liverpool fails to win.

The following is an example of a traditional Las Vegas Parlay Card, which shows the typical payouts for an up to 11 team parlay bet (amount won is assuming $100 is bet):

Many gamblers have mixed feelings as to whether or not parlays are a wise play. The best way to analyze if they are profitable in the long term is by calculating the expected value. The formula for expected value is: E[X] = x1p1 + x2p2 + x3p3…xkpk . Since the probability of all possible events will add up to 1 this can also be looked at as the weighted average of the event. The table below represents odds.

Column 1 = number of individual bets in the parlay

Column 2 = correct odds of winning with 50% chance of winning each individual bet

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Wikipedia